Parasites (Monogenea) of tilapias Oreochromis niloticus and Coptodon rendalli (Cichlidae) in a river spring in Brazil.

In the present study, we examined 30 individuals of introduced African cichlids, Oreochromis niloticus and Coptodon rendalli, collected in a river spring of the Pardo River, Paranapanema River basin, southeastern Brazil. Based on morphological and molecular analyses of the partial LSU rDNA gene, we identified four species of monogeneans, Cichlidogyrus tilapiae, C. thurstonae, C. mbirizei, and Scutogyrus longicornis on the gills of O. niloticus, whereas individuals of C. rendalli were infested only with C. papernastrema. This is the first record of C. mbirizei and C. papernastrema in tilapias from Brazil. The ecological consequences of the introduction of exotic species of tilapia such as O. niloticus and C. rendalli along with their monogenean parasites in a wild environment represented by a river spring are discussed. Our new molecular data on Cichlidogyrus and Scutogyrus contribute to the investigation of the phylogenetic interrelationships of these widely distributed genera of monogeneans since their species composition is still unsettled.

Title: Parasites (Monogenea) des tilapias Oreochromis niloticus et Coptodon rendalli (Cichlidae) dans une source au Brésil. Abstract: Dans la présente étude, nous avons examiné 30 individus de cichlidés africains introduits, Oreochromis niloticus et Coptodon rendalli, collectés dans une source fluviale du fleuve Pardo, bassin du fleuve Paranapanema, dans le sud-est du Brésil. Sur la base d'analyses morphologiques et moléculaires du gène partiel de l'ADNr LSU, nous avons identifié quatre espèces de monogènes, Cichlidogyrus tilapiae, C. thurstonae, C. mbirizei et Scutogyrus longicornis sur les branchies d'O. niloticus, alors que les individus de C. rendalli étaient infestés uniquement par C. papernastrema. Il s'agit du premier signalement de C. mbirizei et C. papernastrema chez des tilapias du Brésil. Les conséquences écologiques de l'introduction d'espèces exotiques de tilapia telles que O. niloticus et C. rendalli ainsi que leurs monogènes parasites dans un environnement sauvage représenté par une source fluviale sont discutées. Nos nouvelles données moléculaires sur Cichlidogyrus et Scutogyrus contribuent à l'étude des interrelations phylogénétiques de ces genres de monogènes largement distribués puisque leur composition spécifique est encore incertaine.

Molecular phylogeny of two Rhinoxenus species (Monogenea: Dactylogyridae) from the nasal cavities of serrasalmids (Characiformes: Serrasalmidae) from Brazil.

The dactylogyrid genus Rhinoxenus (Monogenea: Dactylogyridae) is composed of specialized monogeneans infecting the nasal cavities of freshwater fishes from the Neotropical region. This taxon currently comprises 11 species and is easily distinguished from other monogeneans by the absence of the dorsal bar, ventral anchor with inconspicuous roots covered by a sclerotized cap, dorsal anchor greatly modified into a needle-like shape, and hook pair 2 located into bilateral lobes of the trunk. Specimens of Rhinoxenus euryxenus and Rhinoxenus paranaensis were found infecting the nasal cavities of Serrasalmus marginatus and Serrasalmus maculatus, respectively, from the Paraná River basin in Brazil. For the first time, molecular data of Rhinoxenus spp. were obtained and used as a basis for phylogenetic analyses of the genus. Furthermore, our findings represent the first record of R. paranaensis in Brazil.

Revisiting the taxonomy of Rhabdias fuelleborni Travassos, 1928 (Nematoda, Rhabdiasidae) with approaches to delimitation of species and notes on molecular phylogeny.

Rhabdias fuelleborni was described by Travassos (1926), who identified it in the lungs of Rhinella gr. marina (=Bufo marinus) from São Paulo. Later, Kloss (1971) added new information on the morphology and diagnosis of the species and new data on host and localities. However, its taxonomic status remains uncertain, due in particular to the morphological uniformity of Rhabdias spp., while the original description lacks important morphological data. In the present study, we found and reevaluated the type series of R. fuelleborni, as well as examining fresh material obtained from the type host and type locality, using light and scanning electron microscopy and molecular tools. The type series was deposited by Travassos (1926), and according to museum records the type locality is Paraty, Rio de Janeiro, Brazil. Our morphological and molecular analyses reinforce the taxonomic validity of this species, while molecular phylogeny identified a close relationship between R. fuelleborni and Rhabdias sp.4 and Rhabdias sp. from other studies, and from bufonids. Also R. fuelleborni are sister taxa with R. cf. stenocephala from Leptodactylidae from the northeast of Brazil and R. vencesi from Boophis madagascarariensis, Madagascar, according to mitochondrial COI gene.

Diversity of myxozoans parasitizing the catfish Rhamdia quelen (Siluriformes: Heptapteridae), in southeastern Brazil, based on morphological and molecular evidence.

Rhamdia quelen is a commercially important fish in South America. During the survey of myxozoan infections in fishes from Pardo River, Paranapanema River basin, São Paulo State, Brazil, we describe three new species of Henneguya found parasitizing gills of R. quelen: Henneguya bagre n. sp., Henneguya breviscauda n. sp and Henneguya novaerae n. sp. The descriptions were based on myxospores morphology and small subunit ribosomal DNA partial sequences. Phylogenetic analysis showed a clade formed by species that parasitize Siluriformes, with Henneguya jundiai as a sister species of Henneguya bagre n. sp., Henneguya breviscauda n. sp and Henneguya novaerae n. sp. Our study indicates that the parasites infecting R. quelen belong to a lineage of myxozoans infecting Heptapteridae fishes. Using molecular and morphological characterization, the species were identified as new species for the genus Henneguya. Based on our analysis we recommend monitoring the presence of these parasites in farmed fishes, to analyze possible pathologies caused by them.

Diversity of Haemogregarine Parasites Infecting Brazilian Anurans, with a Description of New Species of Dactylosoma (Apicomplexa: Adeleorina: Dactylosomatidae).

PURPOSE: Brazilian anurans are considered the most diverse and species rich around the world. Although in recent years there has been a strong focus on research related to this group of animals, their parasites have not received the same attention. Thus, this study aimed to provide morphological and molecular data on haemogregarines biodiversity infecting Brazilian anurans. METHODS: During 2020, 116 anurans were collected from four Brazilian States and their blood and fragment of organs were screened for haemogregarine parasites. RESULTS: From the total, seven (6.03%) animals were found infected with species of Hepatozoon and Dactylosoma. Based on the morphological and molecular analysis, four anurans were found infected with Hepatozoon latrensis. The phylogenetic analysis has shown the isolates from this study grouping with the Brazilian anuran Hepatozoon clade, also with gene similarity ranging from 99.70 to 100% to H. latrensis isolates available on GenBank. Furthermore, three specimens (Trachycephalus typhonius, Leptodactylus latrans, and Rhinella diptycha) were infected with the same species of Dactylosoma (100% genetic similarity), with a genetic similarity of 98.56% to Dactylosoma piperis the only other species described in Brazil. In support of the molecular data, different morphological characters were observed in the blood smears as compared to D. piperis, suggesting that the species of Dactylosoma from the present study infecting three different species of Brazilian anurans is an undescribed species. CONCLUSION: Thus, this study increases the knowledge of Brazilian anuran blood parasites and demonstrates the importance of using integrative approaches for the diagnosis of haemoparasites.

Henneguya polarislonga n. sp. (Cnidaria: Myxosporea) parasitizing Astyanax lacustris (Lütken, 1875) with an insight on its life cycle.

Henneguya polarislonga n. sp. is described from the gills of Astyanax lacustris (Lütken, 1875) (Characiformes, Characidae) from streams of the Middle Paranapanema River, Upper Paraná River basin, in the São Paulo State, Brazil. The proposed new species is supported by a combination of morphological and molecular characterization (partial fragment of the SSU rDNA). Thirty specimens of A. lacustris were analyzed and myxospores were found in the gill lamellae of one specimen (Prevalence = 3.3%). Henneguya polarislonga n. sp. was morphometrically and genetically distinct from other Henneguya spp. previously described in Astyanax spp., mainly differing in the total length and caudal appendages length of the mature myxospores. Comparative analysis of the SSU rDNA sequences revealed that Seisactinomyxon-type actinospores previously reported parasitizing oligochaetes are developmental stages of the life cycle of Henneguya polarislonga n. sp. (similarity of 99.9%). This is the first time that an actinospore and a myxospore are correlated through molecular analysis in Brazil, contributing to the knowledge of the myxozoan ecology and biodiversity.

A new species of Tiddergasilus Marques & Boeger, 2018 (Copepoda: Ergasilidae) from the gills of Astyanax lacustris (Lütken) (Osteichthyes: Characidae) in Brazil.

A new parasitic copepod, Tiddergasilus bipartitus n. sp. (Copepoda, Ergasilidae), is described herein based on three adult females found attached to the gills of the yellow-tail lambari Astyanax lacustris (Lütken), sampled in Pardo River, municipality of Botucatu, São Paulo State, Brazil. Tiddergasilus bipartitus n. sp. was recognized as a new member of the monotypic genus Tiddergasilus Marques & Boeger, 2018 by having: antennule 6-segmented; maxillary basis armed with 2 terminal teeth and ornamented with multiple spinules; second and third leg both with endopod 3-segmented. The new copepod can be distinguished from its congener, Tiddergasilus iheringi (Tidd, 1942), by the morphology of the antennal claw, number of somites/segments in abdomen and fourth leg, and by the ornamentation of the first leg. This report expands the geographic distribution and diversity of fish species parasitized with Tiddergasilus spp. in Brazil. Moreover, it also represents the first report of an ergasilid species in the Pardo River. A list of diagnostic features for the Brazilian species of Ergasilus von Nordmann, 1832 is provided herein, in order to aid comparisons with the species of this complex genus.

Taxonomy and Systematics of Two New Species of Myxobolus (Cnidaria: Myxobolidae) Parasitizing the Gills of Mugil curema (Mugilidae) from the Brazilian Coast.

PURPOSE: We describe two new species of Myxobolus (Myxobolidae) found parasitizing Mugil curema from two locations in Brazil: Myxobolus curemae n. sp. from gill arch and rays and Myxobolus maceioensis n. sp. from gill lamellae. METHODS: We based the descriptions on myxospore morphology, histology, and small-subunit ribosomal DNA sequences. RESULTS: Myxospores of the two new species had similar morphology and morphometry but differed in spore body width and length, and ssrDNA sequences differed by 10.5%. These data supported the diagnosis of the parasites as distinct and novel species. The phylogenetic analysis showed a subclade formed by species that parasitize Mugiliformes, with M. maceioensis n. sp. as a sister species of Myxobolus episquamalis and Myxobolus bizerti, while there is a group of six species that are sister related to M. curemae n. sp. Our analysis was consistent with previous studies suggesting that orders of the hosts are strongly correlated with phylogenetic signals in the Myxobolidae. CONCLUSIONS: Myxobolus curemae n. sp. and M. maceioensis n. sp. are new species identified parasitizing M. curema.

Diversity of haemogregarine parasites infecting Brazilian snakes from the Midwest and Southeast regions with a description of two new species of Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae).

Although Brazil is a hotspot for snake species, there is a lack of information on the biodiversity of haemoparasites infecting these hosts. Thus, the present study aimed to bring new insights on the diversity of species of Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae) infecting Brazilian snakes from the Midwest and Southeast regions. The snakes were captured from 2018 to 2020 from the states of Mato Grosso, Mato Grosso do Sul, Goiás, and São Paulo. Three to five blood smears were made and the remaining blood sample was stored for further molecular analysis. Moreover, histopathological slides of the organs were stained with haematoxylin-eosin. Regarding molecular diagnosis, PCR was performed targeting different regions of the 18S rRNA gene of apicomplexan parasites. From the 13 free-living snakes screened, ten (76.92%) were found infected with Hepatozoon spp. Based on morphological and morphometric tools, five different morphotypes of species of Hepatozoon gamonts were detected. Molecular data and phylogenetic analysis support the morphological data, identifying five species of Hepatozoon from snakes, of which three species belong to previously described species, Hepatozoon cevapii, Hepatozoon cuestensis, and Hepatozoon quagliattus, with a genetic similarity of 100% (based on the 18S rRNA genetic marker). The present study identifies and describes two new species of Hepatozoon, Hepatozoon annulatum sp. nov. infecting the snake Leptodeira annulata and Hepatozoon trigeminum sp. nov. infecting the snake Oxyrhopus trigeminus. Thus, based on morphological and molecular data the present study provides new insights on haemogregarine diversity infecting Brazilian snakes from the Midwest and Southeast regions.

Morphological, ultrastructural, and molecular analysis of a new species of Myxobolus (Cnidaria, Myxosporea) parasitizing Apareiodon piracicabae (Characiformes, Parodontidae) from Brazil.

About forty-two species of Myxobolus have been previously described to parasitize characiform fishes in South America. Here, we described a new myxozoan species, Myxobolus parodontidis n. sp., in the gills of Apareiodon piracicabae (Characiformes, Parodontidae) from the streams of the Middle Paranapanema River basin, Brazil. The proposed new species is supported by a combination of morphological, ultrastructural, and molecular characterization (small subunit ribosomal DNA). Thirteen specimens of A. piracicabae were analyzed and 30.8% was infected by Myxobolus parodontidis n. sp. The myxospores was classified as intralamellar asymmetric type. A few aberrant myxospores with three polar capsules were observed: the spore length and width were the same of normal myxospores, but the polar capsules had smaller sizes. Ultrastructural analysis showed that the plasmodial membrane of Myxobolus parodontidis n. sp. was in direct contact with the host tissue and a connective capsule surrounding the plasmodium was not observed. The phylogenetic analysis showed that the main influence in the clustering of species of myxobolids seems to be related to the phylogenetic relationships established among fish hosts, mainly at the level of family and order. This is the first record of a myxozoan species parasitizing parodontid fish, contributing to the knowledge of the biodiversity of myxozoans from Brazil.

Morphological and molecular characterization of the cryptic species Myxobolus cataractae n. sp. (Cnidaria: Myxozoa: Myxobolidae) parasitizing Imparfinis mirini (Siluriformes: Heptapteridae).

We describe Myxobolus cataractae n. sp., found parasitizing Imparfinis mirini from Cachoeirinha stream, a tributary of Pardo River, Paraná River basin, municipality of Botucatu, São Paulo State, Brazil. We based the description on myxospore morphology, histology, and small subunit ribosomal DNA partial sequences. Whitish and elongated mass of myxospores were found in gill filaments, occupying an intrafilamental position. The myxospores were slightly ellipsoidal and the morphometric measurements revealed a myxospore body length of 7.8 ± 0.4 µm; myxospore width of 5.9 ± 0.4 µm; and thickness of 3.9 ± 0.3 µm. The polar capsules are equal in size and measured 3.5 ± 0.2 µm in length and 1.7 ± 0.2 µm in width. The polar tubules had 6-7 coils. Myxobolus cataractae n. sp. is classified as the intrafilamental type and chondreal subtype by the histological analysis of gills. Phylogenetic analysis showed a well-supported subclade formed by species that parasitize gills of Siluriformes, with M. imparfinis as a sister species of Myxobolus cataractae n. sp. Using molecular and morphological characterization, this cryptic species was identified as a new species of the genus Myxobolus.

Description of Two Novel Henneguya (Cnidaria: Myxosporea) Infecting Curimatid Fish, Using Morphological, Histological, and Molecular Analyses.

PURPOSE: We describe two new Henneguya spp. (Myxobolidae) found parasitizing Cyphocharax modestus from Pardo river, Paraná river basin, municipality of Botucatu, São Paulo State, Brazil: Henneguya fastigata n. sp. from gill lamellae and Henneguya pardensis n. sp. from gill arches. We based the descriptions on myxospore morphology, histology, and small subunit ribosomal DNA sequences. METHODS: In this investigation, 50 specimens of Cyphocharax modestus were examined between July and December 2020 for myxozoan infections. Morphological characterization was based on the mature myxospores. The small subunit ribosomal DNA sequences were used for molecular and phylogenetic study. RESULTS: Phylogenetic analysis provided the evolutionary position of these new species with other myxobolids species. Myxospores of the two species had similar morphology and morphometrics, but differed in spore body width and length, and ssrDNA sequences differed by 7.2%. These data supported the diagnosis of the parasites as distinct and novel species. The phylogenetic analysis showed a well-supported subclade formed by species that parasitize curimatid fishes, with Henneguya gilbert as a sister species of Henneguya fastigata n. sp., and Henneguya pardensis n. sp. as a sister species of both species. CONCLUSION: Our analysis was consistent with previous studies suggesting that orders and families of the hosts are strongly correlated with phylogenetic signals in the Myxobolidae. These are the first species of myxozoans described in the Pardo river.

Three new species of Creptotrema (Trematoda, Allocreadiidae) with an amended diagnosis of the genus and reassignment of Auriculostoma (Allocreadiidae), based on morphological and molecular evidence.

Diversity of Creptotrema was investigated using morphological and molecular tools, including data for Creptotrema creptotrema (type-species). Three new species, parasites of Brazilian fishes, are described: Creptotrema conconae n. sp. (type-host, Imparfinis mirini Haseman), Creptotrema schubarti n. sp. (type-host, Characidium schubarti Travassos) and Creptotrema megacetabularis n. sp. (type-host, Auchenipterus osteomystax (Miranda Ribeiro)). The diagnosis of the genus was amended to include new features. The new species differ from each other mainly in terms of body shape, relative sucker size, and testes position. DNA sequences were obtained from Creptotrema spp. from Brazil, including 28S, ITS and COI. Genetic divergences among the new species and C. creptotrema varied from 2.1 to 5.2% (21-49 bp) for 28S, and 6.6 to 16.4% (21-45 bp) for COI. Phylogenetic analysis (28S) placed the newly generated DNA sequences of Creptotrema in a clade (Creptotrema clade sensu stricto) composed of C. creptotrema, the new species described herein, and all species previously described as Auriculostoma, revealing that Auriculostoma is best interpreted as a synonym of Creptotrema based on the principle of priority of zoological nomenclature. Creptotrema funduli, the single sequence of the genus previously available, was not grouped within the Creptotrema clade sensu stricto, suggesting the need for reevaluation of the taxonomic status of this species. Our results showed that Creptotrema represents a monophyletic genus of trematodes widely distributed across the Americas, which currently comprises 19 valid species of parasites of teleosts and anurans.

TITLE: Trois nouvelles espèces de Creptotrema (Trematoda, Allocreadiidae) avec diagnostic modifié du genre et une réattribution d'Auriculostoma (Allocreadiidae) sur la base de preuves morphologiques et moléculaires. ABSTRACT: La diversité de Creptotrema a été étudiée à l'aide d'outils morphologiques et moléculaires, incluant des données pour Creptotrema creptotrema (espèce-type). Trois nouvelles espèces, parasites de poissons brésiliens, sont décrites : Creptotrema conconae n. sp. (hôte-type, Imparfinis mirini Haseman), Creptotrema schubarti n. sp. (hôte-type, Characidium schubarti Travassos) et Creptotrema megacetabularis n. sp. (hôte-type, Auchenipterus osteomystax (Miranda Ribeiro)). Le diagnostic du genre a été modifié pour inclure de nouvelles caractéristiques. Les nouvelles espèces diffèrent les unes des autres principalement en termes de forme du corps, de taille relative des ventouses et de position des testicules. Des séquences d'ADN ont été obtenues de Creptotrema spp. du Brésil, y compris 28S, ITS et COI. Les divergences génétiques entre les nouvelles espèces et C. creptotrema variaient de 2,1 à 5,2 % (21 à 49 pb) pour les séquences 28S, et de 6,6 à 16,4 % (21 à 45 pb) pour le COI. L'analyse phylogénétique (28S) a placé les séquences d'ADN nouvellement générées de Creptotrema dans un clade (Creptotrema clade sensu stricto) composé de C. creptotrema, les nouvelles espèces décrites ici et toutes les espèces précédemment décrites comme Auriculostoma, révélant qu'Auriculostoma est mieux interprété comme un synonyme de Creptotrema sur la base du principe de priorité de la nomenclature zoologique. Creptotrema funduli, la seule séquence du genre précédemment disponible, n'a pas été regroupée au sein du clade Creptotrema sensu stricto, ce qui suggère la nécessité d'une réévaluation du statut taxonomique de cette espèce. Nos résultats montrent que Creptotrema est un genre monophylétique de trématodes largement distribué à travers les Amériques, qui comprend actuellement 19 espèces valides, parasites de téléostéens et d'anoures.

Visceral mycobacteriosis in amphibians from the Brazilian Caatinga region.

Emerging infectious diseases in wild animals related to humans have received greater attention in recent years. Mycobacteriosis is a bacterial disease of animal and human importance. Mycobacterium gordonae infects the skin and internal organs of free-ranging amphibians and is considered the least pathogenic member of the Mycobacteriaceae to humans. However, information about its infection and pathogenesis in wild amphibians is still lacking. A total of 1306 amphibian specimens belonging to 6 families, 12 genera, and 21 species were collected and dissected during a helminthological survey of 7 municipalities in southern Ceará state, Caatinga (eco)region, northeast Brazil. Of these, 17 specimens (0.76%), belonging to 2 families and 4 species (Leptodactylus macrosternum, n = 2; L. vastus, n = 10; Pseudopaludicola pocoto, n = 2; Rhinella jimi, n = 3), presented infections that consisted of calcification nodules in the coelomic cavity, kidney, liver, lung, gut, and pancreas. The nodules were examined by histopathology and PCR. The bacteria were identified as M. gordonae by molecular analyses. Infected animals presented with hepatocellular vacuolar degeneration, karyolysis, and karyorrhexis, hepatic portal congestion, hemorrhage, mononuclear cellular infiltration, melanomacrophage center hyperplasia, and granulomas in varying stages of development with intralesional acid-fast bacilli. This study is the first report of M. gordonae in these amphibian species, in which results of molecular analyses confirmed the presence of M. gordonae in natural environments and histopathology confirmed the typical lesion of mycobacteriosis in amphibians from northeastern Brazil.

Morphological and molecular data of new species of Characithecium and Diaphorocleidus (Monogenea: Dactylogyridae) from Neotropical characid fishes.

The present study describes three new species of monogenean parasites of characid fishes from the Upper Paraná River basin, Brazil: Characithecium paranapanemense n. sp. on Psalidodon paranae and Psalidodon bockmanni, Diaphorocleidus magnus n. sp. on Astyanax lacustris and Psalidodon fasciatus, and Diaphorocleidus neotropicalis n. sp. on Astyanax lacustris and P. bockmanni. An amendment for Diaphorocleidus is proposed, since additional characters observed in the new species required to extend the generic diagnostic features mainly to include: articulation process connecting the base of the MCO with accessory piece present or absent, and accessory piece with variable shapes (plate-like, pincer-shaped, wrench-shaped, sheath-shaped), divided or not into subunits. Characithecium paranapanemense n. sp. can be distinguished from other congeners by the morphology of its MCO and accessory piece. Diaphorocleidus magnus n. sp. differs from most of its congeners by the morphology of its accessory piece, the presence of articulation process connecting the base of the MCO with accessory piece, and the morphology of the sclerotized structures of the haptor. Diaphorocleidus neotropicalis n. sp. can be easily distinguished from its congeners by the morphology of the accessory piece, the sclerotized structures of the haptor and the morphology of the vagina. Molecular data of the new species (partial 28S rDNA and mitochondrial cytochrome oxidase I) were obtained and the first phylogenetic analysis based on 28S rDNA gene sequences for species of Characithecium and Diaphorocleidus are provided. Although Diaphorocleidus and Characithecium share some morphological similarities, phylogenetic analysis indicates that species of these two genera are not closely related.

Characithecium spp. (Monogenea: Dactylogyridae) from Astyanax bimaculatus (Characiformes: Characidae) in Northeast Brazil, with Description of a New Species.

PURPOSE: To date, seven species of Characithecium Mendonza-Franco, Reina and Torchin, 2009 (Monogenea, Dactylogyridae) are valid, parasitizing mainly fishes of the family Characidae (Characiformes) in the Neotropical region. During a parasitological study of fishes in the Batateiras River and Carás stream, Ceará state, Brazil, two species of Characithecium were collected from the gills of Astyanax bimaculatus Linnaeus, 1758 (Characidae). The purpose of the present study is to describe a new species of monogenean of the genus Characithecium and report Characithecium costaricensis Mendoza-Franco, Reina and Torchin, 2009 in A. bimaculatus, in Brazil. METHODS: Monogeneans were isolated from the gills and stored in 70% ethanol, mounted in Gray and Wess' medium or and in a mixture of glycerin ammonium picrate (GAP) to study sclerotized structures. Morphological analyses were performed with a computerized image analysis system with differential interference contrast (DIC). The drawings were obtained with the aid of a camera lucida mounted on a Leica DMLS microscope. RESULTS: Characithecium bifurcuprolatum n. sp. differs from its congenerics by the morphology of the accessory piece having a ventral unit articulated to cirrus base, a non-articulated dorsal and mid-ventral, and a sclerotized vaginal vestibule. Characithecium costaricensis was described from Astyanax aeneus (Günther, 1860) (Characidae) in Central America, and the present finding represents a new geographical and host records in Brazil. Furthermore, we observed the presence of a membrane at the base of the cirrus not mentioned in the original description. CONCLUSION: Our findings increase to eight the number of known species of the genus Characithecium parasitizing characids in neotropics. We verified some additional characteristics present in the two species studied, such as the presence of a membrane at the base of the cirrus, an accessory piece with two subunits (an articulated ventral and a dorsal non-articulated) and the presence of sclerotized vaginal vestibule.

New insights on the diversity of Brazilian anuran blood parasites: With the description of three new species of Hepatozoon (Apicomplexa: Hepatozoidae) from Leptodactylidae anurans.

The Amphibia are considered the most threatened vertebrate class globally, yet in Brazil they are also one of the more diverse and species rich groups. Although, in recent years there has been strong focus on amphibian related research, their parasites have not received the same attention. In Brazil, only a single species of Hepatozoon, namely H. leptodactyli (Lesage, 1908) Pessoa, 1970, has been described from anuran hosts. The present study aimed to describe three new species of Hepatozoon parasitising Leptodactylus labyrinthicus and Leptodactylus latrans from Mato Grosso State, Brazil. From 66 anurans screened for haemogregarines, four belonging to the Leptodactylidae were found positive for species of Hepatozoon. Based on the morphological analysis of peripheral blood gamonts and spleen and liver tissue meronts, three different morphotypes of Hepatozoon spp. were identified. Morphotype 1 (M1) and morphotype 2 (M2) in L. labyrinthicus and morphotype 3 (M3) in L. latrans. Molecular data based on partial 18S rDNA sequences revealed an interspecific divergence, between the species ranging from 0.43% to 1.16%. Phylogenetic analysis recovered isolates from the present study monophyletic with other isolates from Brazilian reptile and anuran hosts, sister to a clade comprising species isolated from African, North American and European reptile and anuran host species. Thus, using morphological and molecular analysis three new species infecting Brazilian Leptodactylidae anurans were identified and described. This study increases the knowledge of Brazilian anurans blood parasites and demonstrates the importance of using integrative approaches for diagnosis of hemoparasites.

Description of a new species of myxobolid parasite, Henneguya pindaibensis n. sp. (Cnidaria: Myxosporea), infecting the gills of Boulengerella cuvieri (Spix and Agassiz, 1829) from Brazil.

Myxozoans are microscopic cnidarians that mainly parasitize fishes. The present study aimed to describe a new myxozoan parasite from the gills of Boulengerella cuvieri (Spix and Agassiz, 1829) by morphological and molecular analysis. The fish was collected in 2019 at the Pindaíba River, municipality of Cocalinho, Mato Grosso State, Brazil. Whitish and circular plasmodia were found in the primary gill filaments, occupying an intralamellar position, with an average of 0.5 mm in diameter. Henneguya Thélohan, 1892 myxospores found inside the plasmodia were elongated and ellipsoidal, consisting of two long and elliptical shell valves with two long, tapering caudal appendages. Morphometric measurements revealed a total spore length of 36.1 ± 2.0 µm; spore body length of 12.8 ± 0.5 µm; spore width of 4.9 ± 0.3 µm; tail length of 23.3 ± 1.6 µm; capsule length of 7.2 ± 0.4 µm; capsule width of 1.5 ± 0.2 µm; and 10 coils in the polar filament. Phylogenetic analysis showed that the isolates from this study were grouped into the main-clade of freshwater fishes, within a group of species parasitizing fishes from Brazil. Intergenotypic difference ranged from 23%-25.9% compared with other Brazilian myxozoan isolates. Using molecular and morphological characterization, this parasite was identified as a new species of the genus Henneguya.

Description of a New Species Hepatozoon quagliattus sp. nov. (Apicomplexa: Adeleorina: Hepatozoidae), infecting the Sleep Snake, Dipsas mikanii (Squamata: Colubridae: Dipsadinae) from Goiás State, Brazil.

PURPOSE: Species of Hepatozoon Miller, 1908 (Hepatozoidae) are blood protozoans with a cosmopolitan distribution and are reported to parasitize a range of vertebrate hosts including mammals, birds, reptiles, and amphibians. The present study aimed to describe a new species of Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae) found infecting the sleep snake Dipsas mikanii (Schlegel, 1837) (Squamata: Colubridae: Dipsadinae). METHODS: The snake was collected in 2017 at the municipality of Britânia, Goiás State, Brazil. Blood smears were made in order to find blood gametocytes and PCR was performed targeting the 18S rRNA gene. RESULTS: Microscopy screening of blood smears revealed the presence of intraerythrocytic gamont stages of Hepatozoon sp. in the peripheral blood with a parasitemia of 0.25%. Furthermore, meronts and monozoic cysts were observed in histological sections of the liver from the infected individual. The interspecific divergence of 18S rRNA sequences fragments isolated from D. mikanii had differences (2.39-11.3%) as compared to other sequences of species of Hepatozoon from snakes. CONCLUSIONS: Based on morphological and molecular data, a new species of Hepatozoon infecting D. mikanii from Brazil is described.

Biodiversity of anuran endoparasites from a transitional area between the Atlantic Forest and Cerrado biomes in Brazil: new records and remarks.

The richness of metazoan endoparasites associated with 25 anuran species from a transitional area between Cerrado and Atlantic Rain Forest from Brazil is here presented. We present and discuss the type-host and localities, the current taxonomic status, remarks on morphological features, biological cycle, and new records of these parasites. Nine hundred and seventy-eight anurans of four families (Bufonidae, Hylidae, Microhylidae, and Leptodactylidae) were collected during four expeditions in a private forested area from Northwest of São Paulo state. The richness of metazoan parasites was composed of nematodes (21), acanthocephalans (2), digeneans (18), monogeneans (1), cestodes (1), and oligochaetes (1), resulting in 44 taxa that are presented with their respective prevalence and the range of abundance in host populations. Among these parasites, nine were found in immature stages which usually complete their life cycle in fishes, snakes, birds or mammals, attesting the trophic relation of amphibians and their parasites within the regional vertebrate community. We reported 23 anuran species as new hosts resulting in 79 new associations between anurans and parasites. Gorgoderina diaster and Bursotrema tetracotyloides are reported for the first time in Brazil, and our finding of Clinostomum cf. complanatum represents the first in South American anurans.